Note: In hotter applications, it is recommended to have
vented fixture housings to release hot air. If fixture is not vented, drilling
holes in the housing is a common venting technique.

By replacing just one 400-watt metal halide bulb and ballast with a 150-watt CFL, you can save up to $360, or 60 percent in energy savings,
over the lifetime of the 10,000-hour bulb, and see a ROI in four months or
less.